Remote Desktop?

I have a server that will not allow anyone to access it remotely. Was working fine two days ago when I last checked it. I have looked over the services, looked over the NIC’s, it can connect to other machines. I thought it might be the port 3398 might not be open, not sure how to actually check it though. I can ping the server, but thats as far as it goes. I can also access the database that is on it. I looked through the registry and found nothing about specific ports other than LPD1-3 and some other random ports. Does anyone have an idea of something I am over looking here?